17
TYPICAL WIRING SCHEMATIC (Sizes 155-300)
LEGEND
AHA —
Adjustable Heat Anticipator
AWG —
American Wire Gage
BRK W/AT—
Breaks with Amp Turns
C—
Contactor, Compressor
CAP —
Capacitor
CB —
Circuit Breaker
CC —
Cooling Compensator
CH —
Crankcase Heater
CLO —
Compressor Lockout
COMP —
Compressor Motor
CR —
Control Relay
CT —
Current Transformer
DAT —
Discharge Air Thermistor
DM —
Damper Motor
DU —
Dummy Terminal
EC —
Enthalpy Control
EQUIP —
Equipment
ER —
EconoMi$er Relay
EPS —
Emergency Power Supply
(9 volt)
FL —
Fuse Link
FLA —
Full Load Amps
FPT —
Freeze Protection Thermostat
FSS —
Filter Status Switch
FU —
Fuse
GND —
Ground
HC —
Heater Contactor
HPS —
High-Pressure Switch
HTR —
Heater
IFC —
Indoor-Fan Contactor
IFCB —
Indoor-Fan Circuit Breaker
IFM —
Indoor-Fan Motor
IFR —
Indoor-Fan Relay
L—
Light
LOR —
Lockout Relay
LPS —
Low-Pressure Switch
LS —
Limit Switch
LSM —
Limit Switch (Manual Reset)
OAT —
Outdoor-Air Thermostat
OFC —
Outdoor-Fan Contactor
OFM —
Outdoor-Fan Motor
OP —
Overcurrent Protection
PL —
Plug Assembly
PRI —
Primary
QT —
Quadruple Terminal
SAT —
Supply Air Thermostat
SW —
Switch
TB —
Terminal Block
TC —
Thermostat Cooling
TH —
Thermostat Heating
TRAN —
Transformer
Terminal (Marked)
Terminal (Unmarked)
Terminal Block
Splice
Factory Wiring
Field Wiring
Option/Accessory Wiring
To indicate common potential
only; not to represent wiring.
NOTES:
1. Compressor and/or fan motor(s) thermally protected; 3-phase motors protected
against primary single-phasing conditions.
2. If any of the original wire furnished must be replaced, it must be replaced with
type 90° C wire or its equivalent.
3. Jumpers are omitted when unit is equipped with EconoMi$er.
5. IFCB must trip amps is equal to or less than 140% FLA.
6. The CLO locks out the compressor to prevent short cycling on compressor over-
load and safety devices. Before replacing CLO, check these devices.
7. Number(s) indicates the line location of used contacts. A bracket over (2) num-
bers signifies a single-pole, double-throw contact. An underlined number signi-
fies a normally closed contact. Plain (no line) number signifies a normally open
contact.
